Visit an auto supply store and you will probably encounter a dozen or more brands of motor oil. You’re likely to find premium products, bargain products, and plenty in between; you will find synthetic, semi-synthetic, and conventional oils, and a range of viscosity grades from 10W-30 to 0W-20 and more.

These choices have something in common: they all carry the familiar Starburst and Donut symbols to show consumers that the oil is of high quality and appropriate for their vehicles. Unless you’re buying a niche product such as racing oil, you should probably walk away from any oil that does not display the symbols. These important indicators are not regulated by a government agency, but licensed by a trade organization: the American Petroleum Institute. Oils branded with the API’s Starburst and Donut have been tested to ensure a level of quality demanded by today’s engines. But who decides what tests the oils have to pass?

A Collaborative Process

The API’s gasoline engine oil specifications are created through an immense collaborative process between automakers and lubricant manufacturers. Every few years, the specifications must be updated to respond to new regulations, changing technology, and consumer demand -- and the process is anything but simple.

Companies like Toyota care about what goes into a new engine oil specification because they want to give their customers the best driving experience, minimize maintenance, and adhere to regulations on emissions and fuel efficiency. Companies like Shell and Lubrizol, on the other hand, want to engineer an oil that earns the automaker’s recommendation -- and is profitable to produce. Representatives from these two groups meet together as the Auto-Oil Advisory Panel (AOAP) to create the specification and devise new tests. The API accepts applications for the panel and ensures that automaker interests and oil company interests are represented equally.

This co-operation began in 1992, when American and Japanese automakers formed a committee called ILSAC (International Lubricant Standardization and Approval Committee). ILSAC named its first gasoline engine oil specification ILSAC GF-1, and the API began licensing its Starburst symbol to motor oils that met that standard. Today, the Starburst represents ILSAC GF-5, which was introduced in 2010. The API’s Service Category -- currently SN -- is derived from the ILSAC standard and displayed in the Donut symbol.

GF-6 to Split in Two

The Auto-Oil Advisory Panel is now working on ILSAC GF-6. The update promises improved fuel efficiency; better protection against wear, corrosion, sludge, and varnish; and defense against low-speed premature ignition. GF-6 will also differ from its predecessors in one key way: it is expected to fork into two distinct categories, GF-6A and GF-6B. GF-6A will remain backwards-compatible with GF-5, while GF-6B will include ultra-low viscosity oils such as SAE 0W-16, and will not be backwards-compatible. This move is similar to the split that occurred between the API’s CK-4 and FA-4 heavy-duty diesel engine oil specifications in 2016. The primary advantage of these lower viscosity oils is improved fuel efficiency.

Low-Viscosity Oils Promise Value Growth

GF-6B oils are expected be in hot demand -- when they finally make it to market. Due largely to the technological complexity of developing new engine tests, the market introduction date of GF-6 has been pushed back from 2017 to 2019. In the meantime, low-viscosity 0W-20 oils licensed under GF-5 will be the fastest-growing grade on the market. Furthermore, these oils are sold at a higher price point because they must contain synthetic basestocks to meet viscosity requirements. As a result, low-viscosity synthetic engine oils will be a bright spot in the engine oil market, which is quickly heading towards flatness in volume terms.